Resin composition having electromagnetic wave shielding effort

ABSTRACT

According to the invention, a resin composition having an electromagnetic wave shielding effect is provided. The resin composition comprises 35 to 90 wt % of an ABS resin or a mixture of the ABS resin and an AS resin, 1 to 25 wt % of a plasticizer and 5 to 40 wt % of carbon fibers. The carbon fibers are uniformly dispersed in the resin ingredient without being broken or cut at the step of mixing and dispersing the resin components, thus exhibiting improved electromagnetic wave shielding effect.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a resin composition having anelectromagnetic wave shielding effect, and more particularly to a resincomposition for shielding the transmission of electromagnetic wavesthereby to prevent disorders or troubles caused by electromagneticwaves.

2. Prior Art

In the conventional systems, electronic instruments, such as businessmachines, electronic computers and television receivers, generateelectromagnetic waves by themselves to cause malfunctions and/or noisesin the neighbouring electronic instruments.

On the other hand, the electronic instruments are affected by theelectromagnetic waves emitted from the adjacent electronic instruments,leading to malfunction thereof or generation of noises therefrom.

Troubles by the electromagnetic waves have been obviated at some extentwhen the housing of such electronic instruments are made of metal platesor aluminum die castings which can shield the transmission ofelectromagnetic waves.

However, plastics materials have been predominantly used for thehousings of electronic instruments in recent years, because of themerits that they are easily molded to have various designs and that theyare light in weight.

However, the plastics materials are generally poor in conductivity andhave substantially no electromagnetic wave shielding effect. It is,thus, necessitated to process the plastics materials to provide themwith electromagnetic wave shielding effect when they are used for thehousing of electronic instruments.

Particularly, in recent years, radiation of electromagnetic waves hasbeen severely prohibited by the domestic and foreign regulations. Underthese circumstances, there is an increasing demand for the plasticsmaterials provided with electromagnetic wave shielding effects.

Various methods for providing the plastic materials with theelectromagnetic wave shielding effect have hitherto been investigated,the known methods including application of an aluminum foil or aconductive tape, flame spraying with molten zinc, coating with aconductive paint, metal plating on the plastics materials, vacuumevaporation coating, spattering ion plating and molding a conductiveplastic material added with a conductive filler.

However, the method of application of an aluminum foil or a conductivetape for the provision of electromagnetic wave shielding effect is notused practically, since it has the disadvantages that extremeskillfullness is required and that it is not suited for the housingshaving complicated shapes.

The method of flame spraying with molten zinc and the method of coatingwith a conductive paint have been predominantly used at the presenttime. However, these methods have the disadvantages that the thicknessof the lining or coating becomes uneven when the housing has acomplicated shape and that the adhesiveness of the lining or coating tothe substrate is insufficient to result in exfoliation of the conductivelayer, leading to the loss of the electromagnetic wave shielding effector even causing a risk of firing.

Although the durability and adhesiveness of the metal plated on theplastics materials are satisfactory, only few kinds of plasticsmaterials can be plated with metals and the articles to be plated arelimited to those of small dimensions.

Satisfactory electromagnetic wave shielding effect can be provided bythe metal evaporation techniques including the vacuum evaporationcoating, spattering and ion plating. However, these techniques have notbeen applied for commercial scale productions, since they requireexpensive apparatuses and skillful operations.

Contrary to the aforementioned methods wherein conductive layers areformed on the surfaces of molded plastics materials to provide theelectromagnetic wave shielding effect, the molded products made of acomposite conductive plastics material containing a conductive fillermixed and dispersed in a matrix plastics material is averted from theimpairment of electromagnetic wave shielding effect or from the risk offiring caused by exfoliation of conductive layer.

However, the known conductive plastics molded articles have thedisadvantages that satisfactory electromagnetic wave shielding effectcannot be obtained unless a large amount of conductive filler is addedto the matrix plastics material, and that the physical properties of theresultant plastics material are deteriorated or the appearance of themolded article is impaired with serious increase in cost as the quantityof the filler added to the matrix plastic material is increased.

Particularly, as the amount of added conductive filler is increased, thedispersibility of the filler is lowered to result in uneven dispersionthereof. Especially when carbon fibers are used for the conductivefiller, the fibers are broken during the kneading step to lower theelectromagnetic wave shielding effect. If some parts of the expensivecarbon fibers are replaced by another inexpensive conductive filler inorder to decrease the content of the carbon fibers, the fibrous andpulverized fillers present in the mixed condition become hardlydispersed in the matrix resin, leading to deterioration of moldabilityof the plastics material and deterioration of the properties of themolded articles. If the resultant plastics material is molded at ahigher temperature in order to improve the moldability thereof, thematrix resin is decomposed or otherwise damaged so that the physicalproperties and the appearance of the molded articles are deterioratedand the coloring property of the resin becomes poor.

OBJECT AND SUMMARY OF THE INVENTION

An object of this invention is to provide a resin composition havingimproved electromagnetic wave shielding effect, comprising a resiningredient and carbon fibers which are uniformly dispersed in the resiningredient and are not substantially broken or cut at the step of mixingand dispersing them.

Another object of this invention is to provide a resin compositionhaving improved electromagnetic wave shielding effect and havingimproved fluidity and excellent moldability.

A further object of this invention is to provide a resin compositionhaving improved electromagnetic wave shielding effect, which can bemolded at a reasonably low melting temperature to avoid deterioration ofphysical properties, appearance and couloring property of the matrixresin.

A still further object of this invention is to provide a resincomposition having improved electromagnetic wave shielding effect, whichhas a flame-retarding property and is improved in thermal and mechanicalproperties.

Yet a further object of this invention is to provide a resincomposition, which has an extremely high electromagnetic wave shieldingeffect and may be coloured freely.

The above and other objects of this invention will become apparent fromthe following description.

The resin composition having an electromagnetic wave shielding effect,according to the present invention, comprises 35 to 90 wt % of acompolymer of an ethylenic unsaturated nitrile, a diene rubber and anaromatic vinyl compound or a mixture of said copolymer with anothercopolymer of ethylenic unsaturated nitrile and an aromatic vinylcompound; 1 to 25 wt % of a plasticizer; and 5 to 40 wt % of carbonfibers.

BRIEF DESCRIPTION OF THE DRAWING

The single figure appended to the specification is a schematicillustration showing the tester for the determination of theelectromagnetic wave shielding effect of the plastics molded articlemade of the resin composition according to the invention.

DESCRIPTION OF THE INVENTION

The present invention will be described in detail hereinbelow.

The matrix resin for the resin composition having an electromagneticwave shielding effect, according to the present invention, is acopolymer of an ethylenic unsaturated nitrile, a diene rubber and anaromatic vinyl compound or a mixture thereof with another copolymer ofan ethylenic unsaturated nitrile and an aromatic vinyl compound.

The ethylenic unsaturated nitrile used in the invention includes, forexample, acrylonitrile, methacrylonitrile, ethacrylonitrile and methylmethacrylonitrile. The particularly preferred are acrylonitrile andmethacrylonitrile.

The diene rubber used in the invention includes one or more ofconjugated 1,3-dienes, such as butadiene, isoprene,2-chloro-1,3-butadiene, 1-chloro-1,3-butadiene and piperylene, whichform rubbery polymers, the particularly preferred being butadiene.

The aromatic vinyl compound used in the invention includes, for example,styrene, α-methylstyrene, vinyltoluene, divinylbenzene andchlorostyrene, which may be used singly or in combination. A favourableresult can be obtained, in the present invention, when styrene is usedsingly as the aromatic vinyl compound.

A more favourable result may be obtained when the copolymer of theethylenic unsaturated nitrile, the diene rubber and the aromatic vinylcompound is a graft copolymer prepared by graft-copolymerizing 20 to 75parts, preferably 20 to 60 parts, by weight of a diene rubber or adiene-containing polymer containing not less than 50 wt % of dienerubber with 80 to 25 parts, preferably 80 to 40 parts, by weight of amixture of an ethylenic unsaturated nitrile and an aromatic vinylcompound.

If a mixture of a copolymer of ethylenic unsaturated nitrile, a dienerubber and an aromatic vinyl compound with another copolymer of anethyleneic unsaturated nitrile and an aromatic vinyl compound is used,the mixing ratio of the former to the latter may range within 25 to 99parts by weight of the former to 1 to 75 parts by weight of the latter,preferably within 35 to 65 parts by weight of the former to 65 to 35parts by weight of the latter. If the mixing ratio is out of theaforementioned range, the moldability and the properties of theresultant composition are deteriorated. The process for the preparationof the copolymers and the mixture thereof are well-known in the art, anddisclosed, for example, in the specification of Japanese PatentPublication No. 37675/1976. The description of the prior publicationreferred to above will be incorporated herein as a reference.

Specific examples of the plasticizers used in the composition of theinvention include phthalic acid esters, such as dibutyl phthalate anddi-2-ethylhexyl phthalate; fatty acid esters, such as di-2-ethylhexyladipate, dibutyl sebacate, di-2-ethylhexyl sebacate and di-2-ethylhexylazelate; epoxides, such as epoxidized fatty acid monoesters, epoxidizedsoybean oil and epoxidized linseed oil; phosphoric acid esters, such astricresyl phosphate, tri-2-ethylhexyl phosphate and tributoxyethylphosphate; ethers, such as triethyleneglycol di-2-ethyl butylate,dibutylcarbitol adipate and dibutylcarbitol formal; polyesters, such asadipic acid polyesters, sebacic acid polyesters and azelaic acidpolyesters; and chlorinated plasticizers, such as chlorinated aliphaticesters and chlorinated paraffins. Particularly preferred plasticizersare phthalic acid esters, phosphoric acid esters and fatty acid esters.

When it is desired to provide the resin composition of the presentinvention with the flame-retarding property, a plasticizer selected fromphosphoric acid derivatives and ethylene/propylene terpolymers is used.

Specific examples of the flame-retarding plasticizers of phosphoric acidderivatives are tri(2-ethylhexyl) phosphate, 2-ethylhexyl diphenylphosphate, tributoxyethyl phosphate, triphenyl phosphate, cresyldiphenyl phosphate, isodecyl diphenyl phosphate, tricresyl phosphate,trixylenyl phosphate, mixed aryl phosphates, phenyl/isopropyl phenylphosphate, mixed triaryl phosphates and tris(chloroethyl) phosphate.Particularly preferred results can be obtained by using 2-ethylhexyldiphenyl phosphate and tricresyl phosphate singly or in combination.

Favorite flame-retarding property may be obtained by using theethylene/propylene terpolymer as the plasticizer in the resincomposition of the invention. The ethylene/propylene terpolymer used asthe plasticizer include copolymers of ethylene and propylene polymerizedwith a small amount of unsaturated compound as the third component. Theterpolymer may be composed to 50 to 80 mol % of ethylene, 20 to 50 mol %of propylene and 0.5 to 10 mol % of an unsaturated third compound, andthe most preferable composition contains 60 to 70 mol % of ethylene, 30to 40 mol % of propylene and 0.5 to 5 mol % of an unsaturated thirdcompound.

Dienes and/or trienes may be generally used as the third unsaturatedcompound, inter alia 1,4-hexadiene, dicyclopentadiene and ethylidenenorbornene are particularly preferred because of their excellentcopolymerizability and low cost.

The content of the plasticizer in the resin composition of the inventionmay range within 1 to 25 wt %, preferably within 2 to 15 wt %. If thecontent of the plasticizer is less than 1 wt %, the viscosity of themolten resin composition at the kneading step becomes too high to causebreakdown of the carbon fibers and to result in insufficient dispersionof the fibers, thereby to lower the electromagnetic wave shieldingeffect and to deteriorate the moldability of the resultant resincomposition. On the contrary, if the content of the plasticizer is morethan 25 wt %, the physical properties including the resistance to heatof the resin composition are lowered and the molded products becomesticky due to bleeding of the plasticizer. When the flame-retardingplasticizer is used, satisfactory flame-retarding effect cannot beexpected if the content thereof is less than 1 wt %. When a phosphoricacid derivative is used as the flame-retarding plasticizer, particularlypreferable content thereof ranges within 2 to 8 wt %. On the other hand,when the ethylene/propylene terpolymer is used as the plasticizer,particularly preferable content thereof ranges within 5 to 10 wt %.

One or a mixture of two or more of carbonized polyacrylonitrile fibers,carbonized pitch fibers and carbonized phenolic compound fibers may beused in the resin composition of the invention. Superior electromagneticwave shielding effect can be attained by using the carbonizedpolyacrylonitrile fibers singly.

It is desirous that the length of individual carbon fiber be preferablyin the range of from 0.5 to 20 mm, most preferably in the range of from2 to 10 mm. If the length of individual fiber is less than 0.5 mm, theconductivity of the resin composition is lowered to an unsatisfactorylevel due to excessively small aspect ratio of the fibers. On thecontrary, if the length of individual fiber is longer than 20 mm, thefluidity of the resin composition is extremely lowered to deterioratethe moldability thereof significantly with attendant deterioration ofthe appearance and mechanical properties of the molded products. Inaddition, the conductivity of the resin composition is rather lowered,since the fibers are not evenly dispersed throughout the composition.The carbon fibers may preferably have the diameters ranging within 3 to25μ, more preferably within 5 to 12μ. The fibers are apt to be brokenunder the shearing action at the kneading step to lessen the aspectratio of the fibers or to be entangled with each other to form fiberballs to lessen the dispersibility thereof, resulting in unsatisfactoryconductivity of the resin composition, if the diameter of individualfibers is less than 3μ. On the contrary, if the diameter of individualfibers is more than 25μ, the conductivity of the resin compositionbecomes unsatisfactory since the aspect ratio of the fibers is toosmall. The bundle count of the carbon fibers may range preferably within1,000 to 20,000, more preferably within 3,000 to 15,000. If the bundlecount is less than 1,000, the bundled fibers are apt to be entangledwith each other to form fiber balls to lessen the dispersibility thereofand to result in unsatisfactory conductivity of the resultant resincomposition. On the contrary, if the bundle count is more than 20,000,the fiber bundles cannot be cloven effectively even by the shearingaction at the kneading step, leading to uneven dispersion of the fibersto result in inferior conductivity of the resin composition.

When it is desired to provide the resin composition with especially highconductivity thereby to improve the electromagnetic shielding effect,carbon fibers with metallized surfaces may be used as the carbon fibersadded to the matrix resin. Such carbon fibers may be produced by coatingthe surfaces of the carbon fibers with a metal, such as Ni, Cu or Al, bythe plating, vacuum evaporation coating or spattering processes.

The content of the carbon fibers in the resin composition should rangewithin 5 to 40 wt %, preferably 10 to 25 wt %. If the content thereof isless than 5 wt %, substantial electromagnetic wave shielding effectcannot be provided. On the contrary, if the content thereof exceeds 40wt %, the resultant resin composition is hardly molded through extrusionor injection molding and the physical properties of the molded productsare deteriorated.

In the present invention, a conductive carbon black may be added to thecomposition in addition to the aforementioned carbon fibers. Specificexamples of the conductive carbon black include furnace black, channelblack and the like such as S.C.F. (Super Conductive Furnace) black,E.C.F. (Electric Conductive Furnace) black, a by-product black such as"Ketchen Black" available from Nippon E. C. Co., Ltd. and acetyleneblack. It is preferred that the carbon black satisfies at least one ofthe following features of:

(1) Having highly developed structure;

(2) Having small particle size;

(3) Having large specific surface area;

(4) Containing only a small amount of impurities which captureelectrons; and

(5) Having high degree of graphitization.

The preferable quantity of the carbon black added to the compositionvaries depending on the kind of the used carbon black, particularly onthe specific surface area thereof, and may range within 2 to 30 wt %,more preferably 3 to 15 wt %. If the added amount of the carbon black isless than 2 wt %, the volume resistivity of the molded product becomesuneven to result in inferior electromagnetic wave shielding effect. Onthe contrary, if the added amount of the carbon black exceeds 30 wt %,the resin composition is hardly molded by extrusion or injection moldingand the physical properties of the molded product become inferior.

An alkylamine antistatic agent may also be added to the resincomposition. Preferable antistatic agents are amine compounds havinghydroxyethyl groups and represented by the following formula of:##STR1## wherein R₁ is an alkyl or alkenyl group having 8 to 22 carbonatoms, and m and n are integers of 1 to 10.

The compounds set forth above are well-known in the art, and it ispreferred to use those represented by the aforementioned formula wherein2≦m+n≦10.

Representative amine compounds having hydroxyethyl groups areN,N-bis(hydroxyethyl) tallow amine, polyoxyethylene lauryl amine andfatty acid esters of polyoxyethylene lauryl amine. Amongst them,N,N-bis(hydroxyethyl) tallow amine is the most preferred.

The amount of the added alkyl amine antistatic agent may range within0.5 to 10 wt %, preferably 1 to 5 wt %. The effect of lowering thevolume resistivity of the molded product cannot be expected when theadded amount of alkyl amine antistatic agent is less than 0.5 wt % sothat the electromagnetic wave shielding effect is not improved. On thecontrary, if the amount of the added alkyl amine antistatic agent ismore than 10 wt %, the resin composition is excessively lubricated toaffect adversely the dispersibility of the carbon fibers at thecompounding step so that the resin composition becomes hardly moldedthrough extrusion or injection molding with attendant undesirableresults that the physical properties and the electromagnetic waveshielding effect of the molded product become inferior.

A halogen-containing organic flame retarder and an auxiliaryflame-retarding agent may also be added to provide the resin compositionwith potent resistance to firing. Specific examples ofhalogen-containing organic flame retarder include chlorinated paraffins,tetrabromobisphenol-A and oligomers thereof, decabromobiphenyl ethers,hexabromobiphenyl ethers, pentabromobiphenyl ethers, pentabromotoluene,pentabromoethylbenzene, hexabromobenzene, pentabromophenol,tribromophenol derivatives, perchloropentanecyclodecane,hexabromocyclododecane,tris(2,3-dibromopropyl-1)-isocyanurate,tetrabromobisphenol-S and derivatives thereof,1,2-bis(2,3,4,5,6-pentabromophenoxy)ethane,1,2-bis(2,4,6-tribromophenoxy)ethane, brominated styrene oligomers,2,2-bis-(4(2,3-dibromopropyl)-3,5-dibromophenoxy)propane,tetrachlorophthalic anhydride and tetrabromophthalic anhydride.

The auxiliary flame-retarding agents which may be used in the resincomposition of the invention include antimony trioxide, sodiumantimonate, zinc borate, and oxides and sulfides of zirconium andmolybdenum, the most favourable result being obtained by the use ofantimony trioxide.

The amount of the halogen-containing organic flame retarder added to theresin composition varies depending on the required degree of flameresistant property and also on the content of the flame-retardingplasticizer, and ranges generally from 2 to 35 wt %, preferably from 5to 25 wt %.

The flame-retarding effect becomes insufficient if the amount of theadded halogen-containing organic flame retarder is less than 2 wt %,whereas the thermal and mechanical properties of the molded productbecome inferior if the amount of added halogen-containing organic flameretarder exceeds 35 wt %.

The added amount of the auxiliary flame-retarding agent may be within0.4 to 21 wt % and the ratio thereof to the halogen-containing organicflame retarder should be within the range of from 6/10 to 2/10,preferably from 5/10 to 3/10. Satisfactory synergistic effect ofretarding the propagation of flame cannot be obtained if the addedamount of the auxiliary flame-retarding agent is less than 0.4 wt %,whereas the mechanical properties of the molded product are deterioratedif the added amount of the auxiliary flame-retarding agent exceeds 21 wt%.

If the ratio of the auxiliary flame-retarding agent to thehalogen-containing organic flame retarder is less than 2/10, synergisticflame-retarding effect cannot be realized to result in unsatisfactoryflame-retarding function, whereas the mechanical properties of themolded product becomes inferior if the ratio of the former to the latterexceeds 6/10.

In order to further improve the properties of the resin composition ofthe invention, antioxidants, internal or external lubricants andstabilizers may be added thereto. Antioxidants which may be added to theresin composition of the invention include phenolic antioxidants, sulfurbase antioxidants and phosphor base antioxidants. Specific examples ofthe phenolic antioxidants are 2,6-di-tert-butyl-p-cresol,2,2'-methylenebis(4-methyl-6-tert-butylphenol),4,4'-butylidenebis(3-methyl-6-tert-butylphenol),4,4'-thiobis(3-methyl-6-tert-butylphenol), butylhydroxyanisole andtetrakis[methylene-3(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]mathane;the specific examples of the sulfur base antioxidants are dilaurylthiodipropionate, distearyl thiodipropionate, lauryl stearylthiodipropionate, dimyristyl thiodipropionate and distearylβ,β'-thiodibutylate; and the specific examples of the phosphor baseantioxidants are tridecyl phosphite, diphenyl phenyl phosphite,triphenyl phosphite and trinonylphenyl phosphite. These antioxidants maybe used singly or in combination. Decomposition or deterioration due tooxidation of the resin composition can be prevented by adding one ormore of the aforementioned antioxidants, preferably, in an amount of0.01 to 4 parts by weight to 100 parts by weight of the resincomposition.

The internal or external lubricants which may be added to the resincomposition of the invention include paraffins and hydrocarbon resins,such as paraffin waxes, liquid paraffins, paraffin base synthetic waxesand polyethylene waxes; fatty acids, such as stearic acid andhydroxystearic acid; fatty acid amides, such as stearoamide,oxystearoamide, oleyl amide, methylenebisstearoamide andmethylenebisbehenamide; fatty acid esters, such as n-butyl stearate,methyl hydroxystearate and esters of saturated fatty acids; fatty acidalcohols, such as higher alcohols, and esters of higher alcohols; andpartial esters of fatty acids and polyhydric alcohols, such as esters ofglycerine and fatty acids, triglyceride of hydroxystearic acid andesters of sorbitan and fatty acids. One or a mixture of two or more ofthe internal or external lubricants set forth above may be used.

The stabilizers which may be added to the resin composition of theinvention include metallic soaps, salts of inorgnic acids, organic tincompounds and composite stabilizers. Specific examples of the metallicsoaps are zinc stearate, calcium stearate, zinc laurate and cadmium2-ethylhexoate; examples of the salts of inorganic acids being tribasiclead sulfate, basic lead sulfite and lead-barium compounds; examples ofthe organic tin compounds being dibutyl tin laurate, dibutyl tindimaleate, and di-n-octyl tin maleate polymers; and examples of thecomposite stabilizers are calcium-zinc base stabilizers, barium-leadbase stabilizers and cadmium-barium-zinc base stabilizers. Thesestabilizers may be used singly or in combination.

Any one or more of the aforementioned internal and/or externallubricants and/or stabilizers may be added to the resin composition,preferably, in a ratio of 0.01 to 4 parts by weight to 100 parts byweight of the resin composition to improve the fluidity of the resincomposition at the molding step and to prevent decomposition ordeterioration of the resinous ingredient.

The process for the preparation of the resin composition of theinvention will now be described. The copolymer of an ethylenicunsaturated nitrile, a diene rubber and an aromatic vinyl compound maybe in the form of powder, bead or pellet. The copolymer or mixturethereof with another copolymer of an ethylenic unsaturated nitrile andan aromatic vinyl compound is mixed with the plasticizer and the carbonfibers and optionally with other ingredients. In order to improve themoldability of the resin composition and to improve the properties ofthe molded products, it is preferred that the ethylenic unsaturatednitrile/diene rubber/aromatic vinyl compound copolymer be in the form ofpowder and the ethylenic unsaturated nitrile/aromatic vinyl compoundcopolymer be in the form of bead. In order to uniformalize or homogenizethe resin composition, the mixture is mixed and kneaded using a kneaderor extruder, such as Bumbury's mixer, cokneader, single spindle extruderor double spindle extruder. The mixture may be subjected to pre-mixingprocess using a tumbler or high speed mixer prior to the mixing andkneading step.

The mixed and kneaded resin composition is then charged in a hopper ofan injection molding machine to be melted in a plasticizing cylinder ofthe injection molding machine, and the molten resin composition isinjected into a mold and then cooled to be solidified. Solidified moldedmass is removed from the mold to obtain an injection molded article madeof the resin composition of the invention. Likewise, the mixed andkneaded resin composition is charged in a hopper of an extuder to bemelted in a plasticizing cylinder of the extruder, and the molten resincomposition is extruded through a die attached to the end of theextruding cylinder to form an extruded product made of the resincomposition of the invention.

EXAMPLES OF THE INVENTION

The present invention will now be described more specifically byreferring to Examples thereof.

EXAMPLES 1 to 8

A powder-form ABS resin (acrylonitrile/butadiene/styrene copolymerresin) having a composition composed of 10 wt % of acrylonitrile, 50 wt% of butadiene and 40 wt % of styrene and a bead-form AS resin(acrylonitrile/styrene copolymer resin) having a composition composed of30 wt % of acrylonitrile and 70 wt % of styrene were used. A plasticizeravailable from Kao Soap Co., Ltd. under the Trade Name "VYNYCIZER #80"was used as the plasticizer in the resin composition. Carbonizedpolyacrylonitrile (referred to as "PAN" in the following Tables) choppedstrands (Length: 6 mm, Diameter: 7μ Bundle Count: 12,000) available fromToho Rayon Co., Ltd. under the Trade Name "BESFIGHT HTAC6S" were used asthe carbon fibers. One part, by weight, for each of an antioxidant andzinc stearate were added to 100 parts, by weight, of the resin. Thecompositions are shown in Table 1. Each of the compositions was put intoa Bumbury's mixer heated to 140° C. to be mixed and kneaded until thetemperature of the mixture reached 190° C. Immediately after the mixturewas discharged from the mixer, it was rolled through mixing rollers toform a sheet which was cooled and then crushed into pellets.

The thus formed pellets were charged in a hopper of an 8-ounce injectionmolding machine to be melted in a plasticizing cylinder of the machine,and then injected into a mold.

The mold was the one provided with a 2 mmφ direct gate for molding ahousing of 15 cm square and having an wall thickness of 3 mm.

The thus molded products had excellent physical properties, improvedresistance to heat and improved electromagnetic wave shielding effect,as shown in Table 1.

EXAMPLES 9 to 11

Each of the compositions set forth in Table 1 was pelletized similarlyto Example 1, and charged in a hopper of an extruder having a cylinderof 40 mm in diameter (L/D=24) to be melted therein at 200° C. The moltenmass was allowed to pass through a die for molding a single layer sheet.

The die had a width of 600 mm and the lip gap was adjusted to 3.5 mm. Asthe result, a single layer sheet having a thickness of 3 mm was formed.

The thus formed single layer sheets had excellent physical properties,improved resistance to heat and improved electromagnetic wave shieldingeffect, as shown in Table 1.

EXAMPLES 12 and 13

A powder-form MBS resin (methacrylonitrile/butadiene/styrene copolymerresin) composed of 50 wt % of methacrylonitrile, 10 wt % of butadieneand 40 wt % of styrene was used in place of the powder-formacrylonitrile/butadiene/styrene copolymer resin. Other ingredients usedin the compositions were the same as used in Example 1. The compositionswere pelletized similarly to Example 1 and then subjected to injectionmolding to form molded products. The properties of the molded productswere tested to reveal that they were improved in physical properties,resistance to heat and electromagnetic wave shielding effect, as shownin Table 1.

EXAMPLE 14

A pellet-form ABS resin (acrylonitrile/butaidene/styrene copolymerresin) composed of 20 wt % of acrylonitrile, 20 wt % of butadiene and 60wt % of styrene was used in place of the ABS resin as used in Example 1to prepare the resin composition shown in Table 1. The resin compositionwas pelletized similarly to Example 1 and subjected to injection moldingto form a molded product. The properties of the molded product weretested to reveal that it had excellent physical properties, improvedresistance to heat and improved electromagnetic wave shielding effect.

COMPARATIVE EXAMPLES 1 and 2

Injection molded products were produced from the compositions set forthin Table 2 in accordance with the procedures similar to Example 1,except in that one composition contained a plasticizer in an amount ofless than the range defined in the claims whereas the other compositioncontained the plasticizer in an amount more than the defined range.

The properties of the injection molded products were tested. The resultsare shown in Table 2.

COMPARATIVE EXAMPLES 3 and 4

Injection molded products were produced from the compositions set forthin Table 2 in accordance with the procedures similar to Example 1,except in that one composition contained carbon fibers in an amount ofless than the range defined in the claims whereas the other compositioncontained carbon fibers in an amount more than the defined range.

The properties of the injection molded products were tested. The resultsare shown in Table 2.

                                      TABLE 1                                     __________________________________________________________________________                      Example No.                                                                    1  2  3   4  5  6  7   8  9 10 11  12 13 14                __________________________________________________________________________    Composition                                                                   Resin                                                                         Powder-Form ABS Resin (wt %)                                                                    32 30 29  31 30 28 30  28 30 30 28  -- -- --                Powder-form MBS Resin (wt %)                                                                    -- -- --  -- -- -- --  -- -- -- --  30 29 --                Bead-form AS Resin (wt %)                                                                       48 45 44  47 45 42 45  42 45 45 42  45 44 --                Pellet-form ABS Resin (wt %)                                                                    -- -- --  -- -- -- --  -- -- -- --  -- -- 75                Plasticizer                                                                   Di-2-ethylhexyl Phthalate (wt %)                                                                 5 10 12  -- -- --  5  10 10 -- 10  10 12 10                Adipic Acid Polyester (wt %)                                                                    -- -- --   7 10 15 --  -- -- 10 --  -- -- --                Carbon Fibers                                                                 PAN Chopped Strand (wt %)                                                                       15 15 15  15 15 15 20  20 15 15 20  15 15 15                Property                                                                      Electromagnetic Wave Shielding                                                                  30 40 45  35 40 50 40  50 35 35 40  40 45 20                Effect (dB)                                                                   Tensile Strength (kg/mm.sup.2)                                                                  3.7                                                                              3.6                                                                              3.5 4.1                                                                              4.0                                                                              3.9                                                                              2.9 2.7                                                                              4.0                                                                              4.4                                                                              3.0 4.0                                                                              3.8                                                                              3.3               Bending Strength (kg/mm.sup.2)                                                                  5.5                                                                              5.4                                                                              5.3 6.0                                                                              5.9                                                                              5.8                                                                              4.3 4.5                                                                              5.9                                                                              6.5                                                                              5.0 5.9                                                                              5.8                                                                              4.9               Bending Modulus of                                                                              260                                                                              240                                                                              220 270                                                                              260                                                                              250                                                                              290 280                                                                              260                                                                              290                                                                              310 260                                                                              270                                                                              240               Elasticity (kg/mm.sup.2)                                                      Izod Impact Strength (kg-cm/cm)                                                                 18 20 22  17 18 21 16  15 22 20 17  16 18 18                Vicat Softening Point (°C.)                                                              80 75 72  82 80 75 80  75 75 80 75  85 82 80                __________________________________________________________________________

                  TABLE 2                                                         ______________________________________                                                          Comparative Example                                                           1    2      3       4                                       ______________________________________                                        Composition                                                                   Resin                                                                         Powder-form ABS Resin (wt %)                                                                      33.8   22     35.2  16                                    Powder-form MBS Resin (wt %)                                                                      --     --     --    --                                    Bead-form AS Resin (wt %)                                                                         50.7   33     52.8  24                                    Pellet-form ABS Resin (wt %)                                                                      --     --     --    --                                    Plasticizer                                                                   Di-2-ethylhexyl Phthalate (wt %)                                                                  0.5    30     10    10                                    Adipic Acid Polyester (wt %)                                                                      --     --     --    --                                     Carbon Fibers                                                                PAN Chopped Strand (wt %)                                                                         15     15      2    50                                    Electromagnetic Wave                                                                              12     40       5>  55                                    Shielding Effect (dB)                                                         Property                                                                      Tensile Strength (kg/mm.sup.2)                                                                    4.5    2.7    4.4   1.6                                   Bending Strength (kg/mm.sup.2)                                                                    6.5    4.5    6.5   2.3                                   Bending Modulus of  300    220    230   280                                   Elasticity (kg/mm.sup.2)                                                      Izod Impact Strength (kg-cm/cm)                                                                   12     22     24    10                                    Vicat Softening Point (°C.)                                                                95     50     75    75                                    ______________________________________                                    

The properties of the molded products set forth in Tables 1 and 2 andthroughout the other Examples and Comparative Examples were determinedby the following test methods.

(1) Electromagnetic Wave Shielding Effect:

Using the tester for the determination of electromagnetic wave shieldingeffect as shown in the appended drawing, the effects of respectivemolded articles were determined through the DENKA method. In detail, aplastics molded article 2 was mounted in a shield box 1 so that thetested article 2 traversed the box 1 to separate the latter into twosections, a high frequency wave emitter antenna 3 being contained in onesection and a receiver antenna 4 being contained in the other section.The high frequency wave emitter antenna 3 was connected to a trackinggenerator 6 which was energized to generate high frequency wave of apredetermined voltage. The wave passing through the traversing article 2was received by the receiver antenna 4. The voltage of the wave passingthrough the article 2 and received by the receiver antenna 4 wascompared with the voltage of the wave emitted from the emitter antenna 3to determine the electromagnetic wave shielding effect of the article 2.

(2) Tensile Strength:

Tensile strengths of respective molded articles were determinedgenerally in accordance with the JIS K-6871 Method.

(3) Bending Strength & Bending Modulus of Elasticity:

These values were determined generally in accordance with the ASTM D-790Method.

(4) Izod Impact Strength(with Notch):

Izod impact strengths of respective molded articles were determinedgenerally in accordance with the JIS K-6871 Method.

(5) Vicat Softening Point:

Vicat softening points of respective molded articles were determinedgenerally in accordance with the JIS K-7206 Method.

EXAMPLES 15 to 29

The powder-form ABS resin(acrylonitrile/butadiene/styrene copolymerresin) as used in Example 1 and the bead-form AS resin(acrylonitrile/styrene copolymer resin) as used in Example 1 were used.The same plasticizer and the same carbon fibers as used in Example 1were used.

At the carbon black used as the one available from Cabot Corp. under theTrade Name "VULCAN XC-72" which had a DBP oil absorption of about 180cm³ /100 g, an N₂ specific surface area of about 180 m² /g and aparticle size of about 30 μm. An alkyl amine antistatic agent availablefrom Kao Soap Co., Ltd. under the Trade Name "ELECTRO STRIPPER-EA" wasused as the antistatic agent.

Each of the compositions set forth in Table 3 was further added with anantioxidant and zinc stearate, and put into a Bumbury's mixer heated to140° C. to be melted and kneaded. Immediately after the temperature ofthe kneaded mixture reached 190° C., the mixture was discharged from themixer and rolled between mixing rollers into a sheet, which was cooledand then crushed into pellets.

The pellets were charged in a hopper of an 8-ounce injection machine tobe melted in the plasticizing cylinder of the machine, and the moltenmass was injected into a mold.

The mold was provided with a 2 mmφ direct gate for molding a housing of15 cm square and having a wall thickness of 3 mm.

The thus molded products had excellent physical properties, improvedresistance to heat and improved electromagnetic wave shielding effect,as shown in Table 3.

EXAMPLES 30 to 34

Each of the compositions as set forth in Table 4 was pelletized inaccordance with the procedures similar to Example 1, and charged in ahopper of an extruder having a cylinder of 40 mm in diameter (L/D=24) tobe melted in the cylinder. The molten composition in the cylinder wasthen extruded through a die for molding a single layer sheet, the diebeing maintained at 200° C.

The die had a width of 600 mm and a lip gap of 3.5 mm. As the result ofextrusion, a single layer sheet having a thickness of 3 mm was formed.

The thus formed single layer sheet had excellent physical properties,improved resistance to heat and improved electromagnetic wave shieldingeffect, as shown in Table 4.

EXAMPLES 35 and 36

A powder-form MBS resin (methacrylonitrile/butadiene/styrene copolymerresin) composed of 50 wt % of methacrylonitrile, 10 wt % of butadieneand 40 wt % of styrene was used in place of the powder-formacrylonitrile/butadiene/styrene copolymer resin used in Example 1. Thecompositions as set forth in Table 4 were pelletized generally followingto the procedures as described in Example 1. Injection molded productswere produced from the thus prepared pellets. The properties of themolded products were tested to reveal that they had improved physicalproperties, improved resistance to heat and improved electromagneticwave shielding effect.

EXAMPLE 37

A pellet-form ABS resin (acrylonitrile/butadiene/styrene copolymerresin) composed of 20 wt % of acrylonitrile, 20 wt % of butadiene and 60wt % of styrene was used. The composition as set forth in Table 4 waspelletized generally following to the procedures as described inExample 1. An injection molded product was formed from the pellets andsubjected to tests. The tesults of the tests revealed that the moldedproduct had improved physical properties, improved resistance to heatand improved electromagnetic wave shielding effect.

COMPARATIVE EXAMPLES 5 and 6

Generally following to the procedures as described in Example 1,injection molded products were produced from the compositions as setforth in Table 4, one composition containing the plasticizer in anamount less than the range defined in the appended claims whereas theother composition containing the plasticizer in an amount more than thedefined range. The properties of the injection molded products are shownin Table 4. As shown, the product of Comparative Example 5 is inferiorin electromagnetic wave shielding effect due to inadequate dispersion ofcarbon fibers, and the product of Comparative Example 6 is inferior inresistance to heat due to excessively high content of plasticizer.

COMPARATIVE EXAMPLES 7 and 8

Generally following to the procedures as described in Example 1,injection molded products were produced from the compositions as setforth in Table 4, one composition containing carbon fibers in an amountless than the range defined in the appended claims whereas the othercomposition containing carbon fibers in an amount more than the definedrange. The properties of the injection molded products are shown inTable 4. As shown, the product of Comparative Example 7 has an inferiorelectromagnetic wave shielding effect, whereas the product ofComparative Example 8 has a low impact strength.

                                      TABLE 3                                     __________________________________________________________________________                      Example No.                                                                   15 16 17 18 19 20 21 22 23 24 25 26 27 28 29                __________________________________________________________________________    Composition                                                                   Resin                                                                         Powder-form ABS Resin (wt %)                                                                    32 30 29 31 30 28 28 26 25 30 29 27 31 29 28                Powder-form MBS Resin (wt %)                                                                    -- -- -- -- -- -- -- -- -- -- -- -- -- -- --                Bead-form AS Resin (wt %)                                                                       48 45 44 47 45 42 42 39 38 45 43 40 47 44 43                Pellet-form ABS Resin (wt %)                                                                    -- -- -- -- -- -- -- -- -- -- -- -- -- -- --                Plasticizer                                                                   Di-2-ethylhexyl Phthalate (wt %)                                                                 5 10 12 -- -- --  5 10 12  7 10 15  5 10 12                Adipic Acid Polyester (wt %)                                                                    -- -- --  7 10 15 -- -- -- -- -- -- -- -- --                Carbon Fibers                                                                 PAN Chopped Strand (wt %)                                                                       10 10 10 10 10 10 20 20 20 10 10 10 10 10 10                Carbon Black                                                                  VULCAN XC-72 (wt %)                                                                              3  3  3  3  3  3  3  3  3  6  6  6  3  3  3                Antistatic Agent                                                              Alkyl Amine Base (wt %)                                                                          2  2  2  2  2  2  2  2  2  2  2  2  4  4  4                Electromagnetic Wave Shielding                                                                  50 60 65 55 60 65 70 80 85 65 70 75 60 70 75                Effect (dB)                                                                   Property                                                                      Tensile Strength (kg/mm.sup.2)                                                                  3.8                                                                              3.7                                                                              3.6                                                                              4.2                                                                              4.1                                                                              4.0                                                                              3.2                                                                              3.1                                                                              3.0                                                                              3.5                                                                              3.4                                                                              3.3                                                                              3.8                                                                              3.7                                                                              3.6               Bending Strength (kg/mm.sup.2)                                                                  5.6                                                                              5.5                                                                              5.4                                                                              6.2                                                                              6.1                                                                              6.0                                                                              5.0                                                                              4.9                                                                              4.8                                                                              5.3                                                                              5.2                                                                              5.1                                                                              5.6                                                                              5.5                                                                              5.4               Bending Modulus of                                                                              270                                                                              250                                                                              230                                                                              290                                                                              280                                                                              270                                                                              320                                                                              300                                                                              280                                                                              300                                                                              280                                                                              260                                                                              270                                                                              250                                                                              230               Elasticity (kg/mm.sup.2)                                                      Izod Impact Strength (kg-cm/cm)                                                                 17 19 21 15 17 19 13 15 17 15 17 19 17 19 21                Vicat Softening Point (°C.)                                                              80 75 72 82 80 75 80 75 72 77 75 70 80 75 72                __________________________________________________________________________

                                      TABLE 4                                     __________________________________________________________________________                      Example No.            Comparative Example                                   30 31 32 33 34 35 36 37  5  6  7   8                         __________________________________________________________________________    Composition                                                                   Resin                                                                         Powder-form ABS Resin (wt %)                                                                   30 30 26 29 29 -- -- -- 34.2                                                                             22 33  14                         Powder-form MBS Resin (wt %)                                                                   -- -- -- -- -- 30 29 --                                      Bead-form AS Resin (wt %)                                                                      45 45 39 43 44 45 44    50.3                                                                             33 50  21                         Pellet-form ABS Resin (wt %)                                                                   -- -- -- -- -- -- -- 75                                       Plasticizer                                                                  Di-2-ethylhexyl Phthalate (wt %)                                                               10 -- 10 10 10 10 12 10 0.5                                                                              30 10  10                         Adipic Acid Polyester (wt %)                                                                   -- 10 -- -- -- -- -- -- -- -- --  --                          Carbon Fibers                                                                PAN Chopped Strand (wt %)                                                                      10 10 20 10 10 10 10 10 10 10  2  50                          Carbon Black                                                                 VULCAN XC-72 (wt %)                                                                             3  3  3  6  3  3  3  3  3  3  3   3                          Antistatic Agent                                                             Alkyl Amine Base (wt %)                                                                         2  2  2  2  4  2  2  2  2  2  2   2                         Electromagnetic Wave Shielding                                                                 50 50 70 60 60 60 65 40 12 60   5>                                                                              90                         Effect dB                                                                     Property                                                                      Tensile Strength (kg/mm.sup.2)                                                                 4.1                                                                              4.5                                                                              3.4                                                                              3.7                                                                              4.1                                                                              4.0                                                                              3.9                                                                              3.3                                                                              4.5                                                                              3.7                                                                              4.4 1.3                        Bending Strength (kg/mm.sup.2)                                                                 6.1                                                                              6.7                                                                              5.4                                                                              5.7                                                                              6.1                                                                              5.9                                                                              5.8                                                                              4.9                                                                              6.6                                                                              4.4                                                                              6.6 2.2                        Bending Modulus of                                                                             280                                                                              310                                                                              330                                                                              310                                                                              280                                                                              260                                                                              240                                                                              240                                                                              310                                                                              230                                                                              230 290                        Elasticity (kg/mm.sup.2)                                                      Izod Impact Strength (kg-cm/cm)                                                                21 19 17 19 21 13 17 18 11 22 25   7                         Vicat Softening Point (°C.)                                                             75 80 75 75 75 85 82 80 95 50 75  75                         __________________________________________________________________________

EXAMPLE 38

Molded products were produced similarly to Example 15 while using thesame resins, the same carbon black and the same antistatic agent.However, the length, diameter and bundle count of the used carbon fiberswere varied as shown in Table 5. The properties of the molded productswere tested similarly to the preceding Examples. The results are shownin Table 5.

                                      TABLE 5                                     __________________________________________________________________________                          Example 38                                                                    Run  Run  Run  Run  Run  Run                                                  1    2    3    4    5    6                              __________________________________________________________________________    Composition                                                                   Resin                                                                         Powder-form ABS Resin (wt %)                                                                        32   32   32   32   32   32                             Powder-form MBS Resin (wt %)                                                                        --   --   --   --   --   --                             Bead-form AS Resin (wt %)                                                                           48   48   48   48   48   48                             Pellet-form ABS Resin (wt %)                                                                        --   --   --   --   --   --                              Plasticizer                                                                  Di-2-ethylhexyl Phthalate (wt %)                                                                     5    5    5    5    5    5                             Adipic Acid Polyester (wt %)                                                                        --   --   --   --   --   --                             Carbon Fibers                                                                 PAN Chopped Strand (wt %)                                                                           10   10   10   10   10   10                             Shape                                                                             Length (mm)       0.2  30    6    6    6    6                                 Diameter (μ)    7    7    1   50    7    7                                 Bundle Count      12000                                                                              12000                                                                              12000                                                                              12000                                                                              500  30000                          Carbon Black                                                                  VULCAN XC-72 (wt %)    3    3    3    3    3    3                             Antistatic Agent                                                              Alkyl Amine Base (wt %)                                                                              2    2    2    2    2    2                             Electromagnetic Wave Shielding Effect (dB)                                                          20   25   20   10   20   25                             Property                                                                      Tensile Strength (kg/mm.sup.2)                                                                      1.4  1.9  3.1  3.4  3.4  3.4                            Bending Strength (kg/mm.sup.2)                                                                      5.0  6.2  4.5  6.2  5.0  6.2                            Bending Modulus of Elasticity (kg/mm.sup.2)                                                         240  300  220  300  240  330                            Izod Impact Strength (kg-cm/cm)                                                                     15    9   13   15   17    9                             Vicat Softening Point (°C.)                                                                  70   80   70   70   75   80                             __________________________________________________________________________

EXAMPLE 39 (Run Nos. 1 to 8)

The same resins and the same carbon fibers as used in Example 1 wereused with a tetrabromobisphenol-A available from Teijin Kasei Limitedunder the Trade Name "FIREGUARD 2000", as a halogen-containing flameretarder, and antimony trioxide produced by Nippon Mining CompanyLimited, as an auxiliary flame-retarding agent.

Further added as a flame-retarding plasticizer of phosphoric acidderivative was tricresyl phosphate produced by Daihachi Kagaku K.K..

The compositions set forth in the following Table 6 were further addedwith an antioxidant, a stabilizer made of tribasic lead and zincstearate, and put into a Bumbury's mixer heated to 140° C. to be meltedand kneaded. Each of the kneaded mixture was discharged from the mixerafter the temperature thereof reached 190° C., and rolled immediatelybetween mixing rollers to form a sheet, which was cooled and thencrushed into pellets.

The pellets were charged in a hopper of an 8-ounce injection moldingmachine to be injected into a mold for molding a housing of 15 cm squareand having a wall thickness of 3 mm, the mold being provided with adirect gate having a diameter of 2 mmφ.

As shown in Table 6, the thus molded products were improved in physicalproperties, resistance to heat and electromagnetic wave shieldingeffect, as well.

EXAMPLE 39 (Run No. 9)

The composition as set forth in Table 6 was pelletized similarly to RunNo. 1 of Example 39, and the pellets were charged in a hopper of anextruder having a cylinder of 40 mm in diameter (L/D=24) to be meltedand extruded through a die for forming a single layer sheet, the diebeing maintained at 200° C.

The die had a width of 600 mm and the lip gap was adjusted to 3.5 mm. Asthe result, a single layer sheet having a thickness of 3 mm was formed.

As shown in Table 6, the thus produced single layer sheet had excellentphysical properties, improved resistance to heat and improvedelectromagnetic wave shielding effect.

EXAMPLE 39 (Run Nos. 10 and 11)

A powder-form MBS resin (methacrylonitrile/butadiene/styrene copolymerresin) composed of 50 wt % of methacrylonitrile, 10 wt % of butadieneand 40 wt % of styrene was used in place of the powder-form ABScopolymer resin used in Run Nos. 7 and 8. The compositions as set forthin Table 6 were pelletized similarly to Run No. 1 of Example 39, andinjection molded products were produced using the thus prepared pellets.The results of tests showed that the molded products had excellentphysical properties, improved resistance to heat and improvedelectromagnetic wave shielding effect.

EXAMPLE 39 (Run No. 12)

A pellet-form ABS resin (acrylonitrile/butadiene/styrene copolymerresin) composed of 20 wt % of acrylonitrile, 20 wt % of butadiene and 60wt % of styrene was used. The composition set forth in Table 6 waspelletized similarly to Run No. 1 of Example 39, and an injection moldedproduct was produced using the thus prepared pellets. The results oftests showed that the molded product had excellent physical properties,improved resistance to heat and improved electromagnetic wave shieldingeffect.

EXAMPLE 39 (Run No. 13)

A composition similar to that of Run No. 2 of Example 39 except in that2-ethylhexyldiphenyl phosphate was used in place of tricresyl phosphate,was pelletized generally following to the procedures as described inExample 1. An injection molded product was produced using the thusprepared pellets, and subjected to tests. The results of the testsshowed that the molded product had excellent physical properties,improved resistance to heat and improved electromagnetic wave shieldingeffect.

                                      TABLE 6                                     __________________________________________________________________________                          Example 39                                                                    Run No.                                                                        1   2  3  4  5  6  7  8  9 10 11 12 13                 __________________________________________________________________________    Composition (wt %)                                                            Resin    Powder-form ABS Resin                                                                      18  20 14 21 15 20 18 20 20 -- -- -- 20                          Powder-form MBS Resin                                                                      --  -- -- -- -- -- -- -- -- 18 20 -- --                          Bead-form AS Resin                                                                         38  42 29 45 31 44 37 42 42 37 42 -- 42                          Pellet-form ABS Resin                                                                      --  -- -- -- -- -- -- -- -- -- -- 62 --                 Flame-Retarding                                                                        2-Ethylhexyl Diphenyl                                                                      --  -- -- -- -- -- -- -- -- -- -- -- 5                           Phosphate                                                            Plasticizer                                                                            Tricresyl Phosphate                                                                         5   5  5  5  5  5  9  2  5  9  2  5 --                 Carbon Fibers                                                                          PAN Chopped Strand                                                                         15  15 10 15 35 10 15 15 15 15 15 15 15                 Flame Retarder                                                                         Tetrabromobisphenol-A                                                                      15  15 30 10 10 15 15 15 15 15 15 15 15                          Antimony Trioxide                                                                           9   3 12  4  4  6  6  6  3  6  6  3  3                 Property                                                                      Electromagnetic Wave Shielding                                                                      40  40 30 40 60 30 40 40 30 40 40 35 40                 Effect (dB)                                                                   Tensile Strength (kg/mm.sup.2)                                                                      2.7 3.0                                                                              2.4                                                                              3.3                                                                              3.3                                                                              3.0                                                                              3.0                                                                              3.0                                                                              3.6                                                                              3.0                                                                              3.0                                                                              2.9                                                                              3.0                Bending Strength (kg/mm.sup.2)                                                                      4.5 5.0                                                                              4.5                                                                              5.0                                                                              6.0                                                                              5.0                                                                              4.5                                                                              5.5                                                                              5.0                                                                              5.0                                                                              5.0                                                                              4.5                                                                              5.0                Bending Modulus of    500 500                                                                              450                                                                              500                                                                              600                                                                              500                                                                              450                                                                              550                                                                              500                                                                              500                                                                              500                                                                              450                                                                              500                Elasticity (kg/mm.sup.2)                                                      Izod Impact Strength (kg-cm/cm)                                                                      8  10  6 12  6 10 12 18 10 10 10  8 10                 Thermal Deformation Temperature (°C.)                                                        90  85 75 90 95 85 80 90 85 85 85 85 85                 Flame-Retarding                                                                        UL-94 Combustion Test                                                                      V-0 V-0                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-0                Property (3" bar)                                                                      Oxygen Index (%)                                                                           31  28 34 25 28 29 29 29 28 29 29 28 28                 __________________________________________________________________________

The properties of the molded product shown in Table 6 and other Tableswere determined by the following test methods.

(1) Thermal Deformation Temperature:

The temperature was determined generally in accordance with the JISK-7207 Method (Load-Flexture Temperature Determination Test for RigidPlastics).

(2) UL-94 Combustion Test:

The test was conducted generally in accordance with the UL-94 VerticalCombustion Test Method.

(3) Oxygen Index:

The oxygen index was determined generally in accordance with the JISK-7201 Method.

EXAMPLE 40 (Run Nos. 1 to 8)

Used as the resinous components were a powder-form ABS resin(acrylonitrile/butadiene/styrene copolymer resin) composed of 10 wt % ofacrylonitrile, 50 wt % of butadiene and 40 wt % of styrene, and abead-form AS resin (acrylonitrile/styrene copolymer resin) composed of30 wt % of acrylonitrile and 70 wt % of styrene. Further added as anethylene/propylene terpolymer was anethylene/propylene/dicyclopentadiene resin produced and sold by MitsuiPetrochemical Industries, Ltd. under the Trade Name "EPT-#1045".

Used as the carbon fibers were carbonized polyacrylonitrile choppedstrands having a fiber length of 6 mm, a fiber diameter of 7μ and aboundle count of 12,000 and available from Toho Rayon Co., Ltd. underthe Trade Name "BESFIGHT HTAC6S". A tetrabromobisphenol-A available fromTeijin Kasei Limited under the Trade Name "FIREGUARD 2000" was used as ahalogen-containing organic flame retarder, and antimony trioxideavailable from Nippon Mining Company, Limited was used as an auxiliaryflame-retarding agent.

The compositions as set forth in Table 7 were further added with anantioxidant, a stabilizer made of tribasic lead and zinc stearate, andthe mixtures were put in a Bumbury's mixer heated to 140° C. Each of thecompositions was discharged from the mixer after the temperature thereofreached 190° C., and processed immediately through mixing rollers toform a sheet, which was cooled and then crushed into pellets.

The pellets were charged in a hopper of an 8-ounce injection moldingmachine to be injected into a mold for molding a housing of 15 cm squareand having a wall thickness of 3 mm, the mold being provided with adirect gate having a port diameter of 2 mmφ.

The thus molded products were excellent in mechanical properties, andimproved in resistance to heat and electromagnetic wave shieldingeffect, as well.

EXAMPLE 40 (Run Nos. 9 to 11)

The compositions as set forth in Table 7 were pelletized similarly toRun No. 1 of Example 40, and the thus prepared pellets were charged in ahopper of an extruder having a 40 mm diameter cylinder (L/D=24) to bemelted and then extruded through a die for forming a single layer sheet,the die being maintained at 200° C.

The die had a width of 600 mm and the lip gap was adjusted to 3.5 mm. Bypasing the molten mass through the die, a single layer sheet having athickness of 3 mm was formed.

As shown in Table 7, the formed single layer sheets were excellent inmechanical properties and resistance to heat and improved inflame-retarding property and electromagnetic wave shielding effect.

EXAMPLE 40 (Run Nos. 12 and 13)

A powder-form MBS resin (methacrylonitrile/butadiene/styrene copolymerresin) composed of 50 wt % of methacrylonitrile, 10 wt % of butadieneand 40 wt % of styrene was used in place of the powder-formacrylonitrile/butadiene/styrene copolymer resin used in Run No. 1 ofExample 40. The compositions as set forth in Table 7 were pelletizedsimilarly to Run No. 1 of Example 40, and injection molded products wereproduced from the thus prepared pellets. The test results of the moldedproducts showed that they were excellent in physical properties,resistance to heat, flame-retarding property and electromagnetic waveshielding effect.

EXAMPLE 40 (Run No. 14)

A pellet-form ABS resin (acrylonitrile/butadiene/styrene copolymerresin) composed of 20 wt % of acrylonitrile, 20 wt % of butadiene and 60wt % of styrene was used to prepare the composition shown in Table 7.The composition was pelletized similarly to Run No. 1 of Example 40 andthen molded to form an injection molded product. The properties of themolded product were tested to find that it had high mechanicalstrengths, excellent resistance to heat, improved flame-retardingproperty and improved electromagnetic wave shielding effect.

EXAMPLE 40 (Run Nos. 15 and 16)

An ethylene/propylene/ethylidenenorbornene terpolymer resin availablefrom Mitsui Petrochemical Industries, Ltd. under the Trade Name"EPT-#3045" was used in place of theethylene/propylene/dicyclopentadiene terpolymer resin used in Run No. 1of Example 40. The compositions as set forth in Table 7 were pelletizedsimilarly to Run No. 1 of Example 40 and then molded to form injectionmolded products. The properties of the molded products were tested tofind that they had high mechanical strengths, excellent resistance toheat, improved flame-retarding property and improved electromagneticwave shielding effect.

COMPARATIVE EXAMPLES 9 and 10

Injection molded products were produced from the compositions as setforth in Table 8 generally following to the procedures as described inRun No. 1 of Example 40, one composition containing anethylene/propylene/dicyclopentadiene terpolymer resin in an amount lessthan the range defined in the claims whereas the other compositioncontaining the same terpolymer resin in an amount of more than thedefined range.

The results of tests for determining the properties of the moldedproducts are shown in Table 8.

COMPARATIVE EXAMPLES 11 and 12

Injection molded products were produced from the compositions as setforth in Table 8 generally following to the procedures as described inRun No. 1 in an amount of less than the range defined in the claimswhereas the other composition containing the carbon fibers in an amountof more than the defined range.

The results of tests for determining the properties of the moldedproducts are shown in Table 8.

The ethylene/propylene/DCPD resin appearing in Table 7 and 8 means aterpolymer of ethylene, propylene and dicyclopentadiene, and theethylene/propylene/ENB resin appearing in the same Tables mean aterpolymer of ethylene, propylene and ethylidenenorbornene.

                                      TABLE 7                                     __________________________________________________________________________                    Example 40                                                                    Run No.                                                                       1  2  3  4  5  6  7  8  9  10 11 12 13 14 1516                __________________________________________________________________________    Composition                                                                   Resin                                                                         Powder-form ABS Resin (wt %)                                                                  19 20 13 22 15 21 18 21 20 18 21 -- -- -- 1920                Powder-form MBS Resin (wt %)                                                                  -- -- -- -- -- -- -- -- -- -- -- 19 20 -- -- -- -Bead-form                                                               AS Resin (wt                                                                 %) 40 43 27 46 3                                                              1 45 38 45 41 38                                                               45 40 43 -- 404                                                              3                   Pellet-form ABS -- -- -- -- -- -- -- -- -- -- -- -- -- 59 -- --               Resin (wt %)                                                                  Ethylene/Propylene Terpolymer                                                 Ethylene/propylene/                                                                           10 10 10 10 10 10 15  5 10 15  5 10 10 10 -- --               DCPD Resin (wt %)                                                             Ethylene/propylene/                                                                           -- -- -- -- -- -- -- -- -- -- -- -- -- -- 1010                ENB Resin (wt %)                                                              Halogen-Containing Organic                                                    Flame Retarder                                                                Tetrabromobisphenol-A (wt %)                                                                  10 10 25  5 10 10 10 10 10 10 10 10 10 10 1010                Auxiliary Flame-Retarding                                                     Agent                                                                         Antimony Trioxide (wt %)                                                                       6  2 10  2  4  4  4  4  4  4  4  6  2  6 62                  Carbon Fibers                                                                 PAN Chopped Strand (wt %)                                                                     15 15 15 15 30 10 15 15 15 15 15 15 15 15 1515                Property                                                                      Tensile Strength (kg/mm.sup.2)                                                                2.7                                                                              3.0                                                                              2.4                                                                              3.3                                                                              3.0                                                                              3.0                                                                              3.0                                                                              3.0                                                                              3.3                                                                              3.3                                                                              3.3                                                                              3.0                                                                              3.3                                                                              2.7                                                                              2.73.0              Bending Strength (kg/mm.sup.2)                                                                4.5                                                                              5.0                                                                              4.5                                                                              5.0                                                                              6.0                                                                              5.0                                                                              4.5                                                                              5.5                                                                              5.5                                                                              5.0                                                                              6.0                                                                              5.0                                                                              5.5                                                                              5.0                                                                              4.5 5.0             Bending Modulus of                                                                            450                                                                              500                                                                              450                                                                              500                                                                              600                                                                              500                                                                              450                                                                              550                                                                              550                                                                              500                                                                              600                                                                              500                                                                              550                                                                              500                                                                              450500              Elasticity (kg/mm.sup.2)                                                      Izod Impact     12 13 10 14 10 13 14 12 13 13 13 13 14 13 1011                Strength (kg-cm/cm)                                                           Thermal Deformation                                                                           90 95 80 95 100                                                                              95 90 95 95 90 95 85 90 85 9095                Temperature (°C.)                                                      Flame-Retarding V-0                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-1                                                                              V-0                                                                              V-0                                                                              V-0                                                                              V-0V-0              Property (1/8 inch bar)                                                       Oxygen Index (%)                                                                              32 29 35 26 26 32 32 26 26 29 23 31 28 31 3532                Electromagnetic Wave                                                                          40 40 40 40 60 30 40 40 35 35 35 40 40 40 4040                Shielding Effect (dB)                                                         Molding Process INJ                                                                              INJ                                                                              INJ                                                                              INJ                                                                              INJ                                                                              INJ                                                                              INJ                                                                              INJ                                                                              EXT                                                                              EXT                                                                              EXT                                                                              INJ                                                                              INJ                                                                              INJ                                                                              INJINJ              __________________________________________________________________________     Note:                                                                         INJ in the Table means injection molding, and EXT in the Table means          extrusion molding.                                                       

                                      TABLE 8                                     __________________________________________________________________________                           Comparative Example                                                           9   10  11  12                                         __________________________________________________________________________    Composition                                                                   Resin                                                                         Powder-form ABS Resin (wt %)                                                                         13  22.2                                                                              10  24                                         Powder-form MBS Resin (wt %)                                                                         --  --  --  --                                         Bead-form AS Resin (wt %)                                                                            28  48.3                                                                              21  50                                         Pellet-form ABS Resin (wt %)                                                                         --  --  --  --                                          Ethylene/Propylene Terpolymer                                                Ethylene/propylene/DCPD Resin (wt %)                                                                 30  0.5 10  10                                         Ethylene/propylene/ENB Resin (wt %)                                                                  --  --  --  --                                         Halogen-Containing Organic Flame Retarder                                     Tetrabromobisphenol-A (wt %)                                                                         10  10  10  10                                         Auxiliary Flame-Retarding Agent                                               Antimony Trioxide (wt %)                                                                              4   4   4   4                                         Carbon Fibers                                                                 PAN Chopped Strand (wt %)                                                                            15  15  45   2                                         Property                                                                      Tensile Strength (kg/mm.sup.2)                                                                       2.3 3.1 3.0 3.0                                        Bending Strength (kg/mm.sup.2)                                                                       3.5 5.5 7.0 5.5                                        Bending Modulus of Elasticity (kg/mm.sup.2)                                                          340 560 700 550                                        Izod Impact Strength (kg-cm/cm)                                                                      20   8   4  12                                         Thermal Deformation Temperature (°C.)                                                         65  100 100 95                                         Flame-Retarding Property (1/8 inch bar)                                                              V-0 below                                                                             below                                                                             V-0                                                                   V-2 V-2                                            Oxygen Index (%)       32  21  21  32                                         Electromagnetic Wave Shielding Effect (dB)                                                           43  37  above                                                                             below                                                                     70  10                                         Molding Process        INJ INJ INJ INJ                                        __________________________________________________________________________     Note: INJ in the Table means injection molding.                          

EXAMPLE 41 (Run Nos. 1 to 6)

Used as the resin components were a powder-form ABS resin(acrylonitrile/butadiene/styrene copolymer resin) composed of 10 wt % ofacrylonitrile, 50 wt % of butadiene and 40 wt % of styrene, and abead-form AS resin (acrylonitrile/styrene copolymer resin) composed of30 wt % of acrylonitrile and 70 wt % of styrene. The used plasticizerwas a tricresyl phosphate available from Daihachi Kagaku K.K., and theused conductive filler was the nickel-plated carbonizedpolyacrylonitrile chopped strands having a fiber length of 6 mm, a fiberdiameter of 7μ and a bundle count of 12,000, available from Toho RayonCo., Ltd. under the Trade Name "BESFIGHT M.C.".

1 part by weight of an antioxidant and 1 part by weight of zinc stearatewere added to 100 parts by weight of the resinous components of eachcomposition to prepare each of the compositions set forth in Table 9.Each of the compositions was put in a Bumbury's mixer heated to 140° C.,to be mixed and kneaded. After the temperature of the mixture reached190° C., the mixture was discharged from the mixer and then immediatelyrolled through mixing rollers to form a sheet, which was cooled and thencrushed into pellets.

The pellets were charged in a hopper of an 8-ounce injection moldingmachine to be melted and then injected into a mold for molding a housingof 15 cm square and having a wall thickness of 3 mm, the mold beingprovided with a direct gate having a port diameter of 2 mmφ.

The thus molded products had excellent physical properties, improvedelectromagnetic wave shielding effect, excellent resistance to heat andgood appearance.

EXAMPLE 41 (Run Nos. 7 and 8)

The compositions as set forth in Table 9 were pelletized similarly toRun No. 1 of Example 41, and the pellets were charged in a hopper of anextruder having a cylinder of 65 mm in diameter (L/D=25) to be meltedand then extruded through a die for forming a single layer sheet.

The die had a width of 600 mm and the lip gap was adjusted to 3.5 mm. Bypassing the molten mass through the die, a single layer sheet having athickness of 3 mm was produced.

The thus formed single layer sheets had excellent physical properties,improved electromagnetic wave shielding effect, excellent resistance toheat and good appearance, as shown in Table 9.

EXAMPLE 41 (Run Nos. 9 and 10)

A powder-form MBS resin (methacrylonitrile/butadiene/styrene copolymerresin) composed of 40 wt % of methacrylonitrile, 20 wt % of butadieneand 40 wt % of styrene was used in place of the powder-formacrylonitrile/butadiene/styrene copolymer resin used in Example 41 RunNos. 1 and 2 to prepare the compositions as set forth in Table 9. Thecompositions were pelletized similarly to Run No. 1 of Example 41, andinjection molded products were produced from the pellets. Test resultsrevealed that the molded products had excellent physical properties,excellent resistance to heat, improved electromagnetic wave shieldingeffect and good appearance.

EXAMPLE 41 (Run No. 11)

A pellet-form ABS resin (acrylonitrile/butadiene/styrene copolymerresin) composed of 20 wt % of acrylonitrile, 20 wt % of butadiene and 60wt % of styrene was used to prepare the composition as set forth inTable 9. The composition was pelletized similarly to Run No. 1 ofExample 41, and an injection molded product was produced from thepellets. The test results revealed that the molded product had excellentphysical properties, excellent resistance to heat, improvedelectromagnetic wave shielding effect and good appearance.

EXAMPLE 41 (Run No. 12)

As shown in Table 9, copper-plated carbon fibers were used in place ofthe conductive filler as used in Run No. 1 of Example 41. An injectionmolded product was produced from the composition generally following tothe procedures as described in Run No. 1 of Example 41. An injectionmolded product was produced from the composition generally following tothe procedures as described in Run No. 1 of Example 41. The test resultsrevealed that the molded product had excellent physical properties,excellent resistance to heat, improved electromagnetic wave shieldingeffect and good appearance.

EXAMPLE 41 (Run Nos. 13 and 14)

Injection molded products were produced similarly to Run No. 1 ofExample 41, except in that dioctylphthalate (DOP) produced by DaihachiKagaku K.K. was used in place of the plasticizer used in Run No. 1 ofExample 41. The compositions are shown in Table 9. The test resultsrevealed that the molded products had excellent physical properties,excellent resistance to heat, improved electromagnetic wave shieldingeffect and good appearance.

COMPARATIVE EXAMPLES 13 and 14

Injection molded products were produced similarly to Run No. 1 ofExample 41, except in that one composition contained Ni-plated carbonfibers in an amount of less than the defined range whereas the othercomposition contained the Ni-plated carbon fibers in an amount of morethan the defined range, as shown in Table 10.

The properties of the injection molded products are shown in Table 10.

COMPARATIVE EXAMPLE 15

An injection molded product was produced similarly to Run No. 1 ofExample 41, except in that brass fibers available from Aisin Seiki Co.,Ltd. under the Trade Name "AISIN METAL FIBER" were used in place of theconductive filler used in Run No. 1 of Example 41.

The properties of the injection molded product are shown in Table 10.

                                      TABLE 9                                     __________________________________________________________________________                       Example 41                                                                    Run No.                                                                       1  2  3  4  5  6  7  8  9  10 11 12  13 14                 __________________________________________________________________________    Composition (wt %)                                                            Resin Powder-form ABS Resin                                                                      30 40 30 25 25 30 30 40 -- -- -- 30  30 30                       Powder-form MBS Resin                                                                      -- -- -- -- -- -- -- -- 30 40 -- --  -- --                       Bead-form AS Resin                                                                         50 45 45 45 35 30 50 40 50 40 -- 50  45 35                       Pellet-form ABS Resin                                                                      -- -- -- -- -- -- -- -- -- -- 80 --  -- --                 Plasticizer                                                                         Tricresyl Phosphate                                                                         5  5 10 15  5 20  5  5  5  5  5  5  -- --                       Dioctyl Phthalate                                                                          -- -- -- -- -- -- -- -- -- -- -- --  10 20                 Conductive                                                                          Ni-Plated Carbon Fibers                                                                    15 10 15 15 35 20 15 15 15 15 15 --  15 15                 Filler                                                                              Cu-Plated Carbon Fibers                                                                    -- -- -- -- -- -- -- -- -- -- -- 15  -- --                       Carbon Fibers                                                                              -- -- -- -- -- -- -- -- -- -- -- --  -- --                       Brass Fibers -- -- -- -- -- -- -- -- -- -- -- --  -- --                 Property                                                                      Electromagnetic Weave Shielding                                                                  65 50 65 70 85 75 55 50 65 60 60 65  55 60                 Effect (dB)                                                                   Tensile Strength (kg/mm.sup.2)                                                                   4.0                                                                              4.2                                                                              3.8                                                                              3.7                                                                              3.1                                                                              3.4                                                                              3.7                                                                              3.6                                                                              4.1                                                                              4.3                                                                              3.8                                                                              3.9 3.9                                                                              3.7                Bending Strength (kg/mm.sup.2)                                                                   6.0                                                                              6.4                                                                              5.5                                                                              5.4                                                                              4.9                                                                              5.0                                                                              6.1                                                                              6.3                                                                              6.1                                                                              6.2                                                                              5.5                                                                              5.8 5.4                                                                              5.1                Bending Modulus of 500                                                                              480                                                                              500                                                                              540                                                                              610                                                                              600                                                                              490                                                                              500                                                                              500                                                                              520                                                                              480                                                                              480 500                                                                              490                Elasticity (kg/mm.sup.2)                                                      Izod Impact Strength (kg-cm/cm)                                                                  10 13 11 13  7  8  9  9  9 10  9 10   9 11                 Vicat Softening Point (°C.)                                                               80 78 75 72 74 75 78 75 82 80 78 76  79 77                 Appearance         o  o  o  o  o  o  o  o  o  o  o  o   o  o                  __________________________________________________________________________     Note:                                                                         Appearance was visually appraised.                                            The mark o indicates that the surface is excellent in smoothness,             the mark Δ indicates that the surface is fairly smooth, and             the mark x indicates that the surface is rough or rugged.                

                  TABLE 10                                                        ______________________________________                                                               Comparative                                                                  Example                                                                       13   14     15                                          ______________________________________                                        Composition (wt %)                                                             Resin    Powder-form ABS Resin                                                                           33     20   30                                              Powder-form MBS Resin                                                                           --     --   --                                              Bead-form AS Resin                                                                              60     30   50                                              Pellet-form ABS Resin                                                                           --     --   --                                    Plasticizer                                                                             Tricresyl Phosphate                                                                              5      5    5                                              Dioctyl Phtalate  --     --   --                                    Conductive                                                                              Ni-Plated Carbon Fibers                                                                          2     45   --                                    Filler    Cu-Plated Carbon Fibers                                                                         --     --   --                                              Carbon Fibers     --     --   --                                              Brass Fibers      --     --   15                                    Property                                                                      Electromagnetic Wave Shielding Effect (dB)                                                             5     90     30                                      Tensile Strength (kg/mm.sup.2)                                                                        5.0    2.0    2.8                                     Bending Strength (kg/mm.sup.2)                                                                        7.0    3.2    4.3                                     Bending Modulus of Elasticity (kg/mm.sup.2)                                                           300    500    480                                     Izod Impact Strength (kg-cm/cm)                                                                       20      4      4                                      Vicat Softening Point (°C.)                                                                    82     75     75                                      Appearance              o      x      x                                       ______________________________________                                         Note:                                                                         Appearance was visually appraised.                                            The mark o indicates that the surface is excellent in smoothness,             the mark Δ indicates that the surface is fairly smooth, and             the mark x indicates that the surface is rough or rugged.                

Although the invention has been described by referring to specificexamples, it should be interpreted that the present invention is notlimited only to the specific examples as herein disclosed, but it isintended to embrace all modifications and alternations included in thebroad scope of the invention as defined in the appended claims.

What is claimed is:
 1. A resin composition having an electromagneticwave shielding effect, comprising:35 to 90 wt % of a copolymer of anethylenic unsaturated nitrile, a diene rubber and an aromatic vinylcompound or a mixture of said copolymer with another copolymer of anethylenic unsaturated nitrile and an aromatic vinyl compound; 1 to 25 wt% of a plasticizer; 5 to 40 wt % of carbon fibers, said carbon fibersbeing selected from the group consisting of carbonized polyacrylonitrilefibers, carbonized pitch fibers, carbonized phenolic compound fibers andmixtures thereof; and 0.5 to 10 wt % of an alkylamine anistatic agent.2. The resin composition according to claim 1, wherein said ethylenicunsaturated nitrile is selected from the group consisting ofacrylonitrile, methacrylonitrile, ethacrylonitrile and methylmethacrylonitrile, said diene rubber is selected from the groupconsisting of butadiene, isoprene, 2-chloro-1,3-butadiene,1-chloro-1,3-butadiene, piperylene and mixtures thereof, and saidaromatic vinyl compound is selected from the group consisting ofstyrene, α-methylstyrene, vinyltoluene, divinylbenzene, chlorostyreneand mixtures thereof.
 3. The resin composition according to claim 1,wherein said copolymer of said ethylenic unsaturated nitrile, said dienerubber and said aromatic vinyl compound is a graft copolymer prepared bygraft-copolymerizing 20 to 75 parts by weight of a diene rubber or adiene-containing polymer containing not less than 50 wt % of dienerubber with 80 to 25 parts by weight of a mixture of an ethylenicunsaturated nitrile and an aromatic vinyl compound.
 4. The resincomposition according to claim 1, wherein said composition is a mixtureof 25 to 99 parts by weight of said copolymer of said ethylenicunsaturated nitrile, said diene rubber and said aromatic vinyl compoundand 1 to 75 parts by weight of said another copolymer of the ethylenicunsaturated nitrile and the aromatic vinyl compound.
 5. The resincomposition according to claim 1, wherein said plasticizer is selectedfrom the group consisting of phthalic acid esters, fatty acid esters,epoxides, phosphoric acid esters, ethers, polyesters and chlorinatedplasticizers.
 6. The resin composition according to claim 5, whereinsaid phthalic acid esters are one or more of dibutyl phthalate anddi-2-ethylhexyl phthalate; said fatty acid esters are one or more ofdi-2-ethylhexyl adipate, dibutyl sebacate, di-2-ethylhexyl sebacate anddi-2-ethylhexyl azelate; said epoxides are one or more of epoxidizedfatty acid monoesters, epoxidized soybean oil and epoxydized linseedoil; said phosphoric acid esters are one or more of tricresyl phosphate,tri-2-ethylhexyl phosphate and tributoxyethyl phosphate; said ethers areone or more of triethyleneglycol di-2-ethyl butylate, dibutylcarbitoladipate and dibutyicarbitol formal; said polyesters are one or more ofadipic acid polyesters, sebacic acid polyesters and azelaic acidpolyesters; and said chlorinated plasticizers are one or more ofchlorinated aliphatic esters and chlorinated paraffins.
 7. The resincomposition according to claim 1, wherein said plasticizer is selectedfrom the group consisting of flame-retarding plasticizers of phosphoricacid derivatives and ethylene/propylene terpolymers.
 8. The resincomposition according to claim 7, wherein said flame-retardingplasticizers are selected from the group consisting of tri(2-ethylhexyl)phosphate, 2-ethylhexyl diphenyl phosphate, tributoxyethyl phosphate,triphenyl phosphate, cresyl diphenyl phosphate, isodecyl diphenylphosphate, tricresyl phosphate, trixylenyl phosphate, mixed arylphosphates, phenyl/isopropyl phenyl phosphate, mixed triaryl phosphatesand tris(chloroethyl) phosphate.
 9. The resin composition according toclaim 7, wherein said terpolymer has a composition containing 50 to 80mol % of ethylene, 20 to 50 mol % of propylene and 0.5 to 10 mol % of anunsaturated compound having a double bond.
 10. The resin compositionaccording to claim 9, wherein said unsaturated compound is selected fromthe group consisting of 1,4-hexadiene, dicyclopentadiene and ethylidenenorbornene.
 11. The resin composition according to claim 1, wherein eachof said carbon fibers has a length of 0.5 to 20 mm and a diameter of 3to 25μ and said carbon fibers have a bundle count of 1,000 to 20,000.12. The resin composition according to claim 1, wherein said alkylamineantistatic agent is an amine compound having hydroxyethyl groups andreparesented by the following formula of: ##STR2## wherein R₁ is analkyl or alkenyl group having 8 to 22 carbon atoms, and m and n areintegers of 1 to
 10. 13. The resin composition according to claim 12,wherein said amine compound is selected from the group consisting ofN,N-bis(2-hydroxyethyl) tallow amine, polyoxyethylene lauryl amine andfatty acid esters of polyoxyethylene lauryl amine.
 14. The resincomposition according to claim 1, further comprising any one or more ofantioxidants, internal and external lubricants, and stabilizers.
 15. Theresin composition according to claim 1, further comprising 2 to 35 wt %of a halogen-containing organic flame retarder and 0.4 to 21 wt % of anauxiliary flame-retarding agent, the amount of added auxiliaryflame-retarding agent being 6/10 to 2/10 of the weight of saidhalogen-containing organic flame retarder.
 16. The resin compositionaccording to claim 15, wherein said halogen-containing organic flameretarder is selected from the group consisting of chlorinated paraffins,tetrabromobisphenol-A and oligomers thereof, decarbromobiphenyl ethers,hexabromobiphenyl ethers, pentabromobiphenyl ethers, pentabromotoluene,pentabromoethylbenzene, hexabromobenzene, pentabromophenol,tribromophenol derivatives, perchloropentanecyclodecane,hexabromocyclododecane, tris)2,3-dibromopropyl-1-)-isocyanurate,tetrabromobisphenol-S and derivatives thereof,1,2-bis(2,3,4,5,6-pentabromophenoxy)ethane,1,2-bis(2,4,6-tribromophenoxy)ethane, brominated styrene oligomers,2,2-bis-(4-(2,3-dibromopropyl)-3,5-dibromophenoxy)propane,tetrachlorophthalic anhydride, tetrabromophthalic anhydride and mixturethereof.
 17. The resin composition according to claim 15, wherein saidauxiliary flame-retarding agent is selected from the group consisting ofantimony trioxide, sodium antimonate, zinc borate, and oxides andsulfides of zirconium and molybdenum.